TCS T4-LED, HO Scale Motor Decoder:
The T4-LED has added Blue and Black/White wires to use a KeepAlive device. This model now includes a 2-pin JST Plug for the KA-P Family of KeepAlive® devices. This decoder may be hard-wired or plugged directly into any locomotive with a 9-pin JST plug.  The onboard resistors on this decoder allow for LED installations without the need for external resistors for F0F, F0R, F1, or F2.
 
Use the standard T4X decoder if your locomotive uses incandescent bulbs.
 
Note: As of August 2022, All T4-LED decoders now come equipped with a plug/jack for a Keep Alive® with the corresponding connector.
 
Back EMF Load Compensation: Provides superior slow speed control and high performance under load.
Quiet Drive: Super-quiet motor control for "buzz" free motor performance.
DC Mode: Decoder will automatically detect DC power. You can also configure how your lighting effects function on DC.
RailCom®: This feature allows the decoder to talk to the command station. RailCom supports expansion for new features.
Variable Momentum: Allows you to make custom acceleration and deceleration curves.
LED Support: This product does not require external resistors when connecting LED's.
Function Remapping: Buttons 0 through 12 may be used to control the lighting functions of this decoder.
Programmable Lighting Effects: Choose from 20 separate user-programmable lighting effects!
Dimmable Brightness: Configure multiple different brightness levels for your LED's or incandescent bulbs.
Decoder Lock: Feature which prevents accidental/unwanted programming while activated.
Airwire™ Compatible: Fully compatible with Airwire™ operation.
User-Loadable Speed Tables: Configure custom speed curves and set speed limits.
 
MSRP is $19.95. (Picture courtesy of TCS.)